This section provides background information related to the present disclosure which is not necessarily prior art.
FIG. 1 is a view showing an example of a conventional semiconductor light-emitting device. The semiconductor light-emitting device includes a substrate 100, a buffer layer 200 grown on the substrate 100, an n-type semiconductor layer 300 grown on the buffer layer 200, an active layer 400 grown on the n-type semiconductor layer 300, a p-type semiconductor layer 500 grown on the active layer 400, a current spreading electrode 600 formed on the p-type semiconductor layer 500, a p-side bonding pad 700 formed on the current spreading electrode 600, an n-side electrode 800 formed on the n-type semiconductor layer 300 exposed by mesa-etching the p-type semiconductor layer 500 and the active layer 400, and a protective film 900.
FIG. 2 is a view showing an example of a conventional vertical-type semiconductor light-emitting device. An n-type semiconductor layer 300, an active layer 400 and a p-type semiconductor layer 500 are grown as in the semiconductor light-emitting device shown in FIG. 1, and then the substrate 100 is removed. A current spreading electrode 600 and a p-side bonding pad 700 are formed on the p-type semiconductor layer 500, while an n-side electrode 800 is formed on the n-type semiconductor layer 300. As compared with the semiconductor light-emitting device shown in FIG. 1, the vertical-type semiconductor light-emitting device has advantages in that current spreading can be facilitated in the light-emitting device and that wire bonding can be reduced. However, a laser is used to remove the substrate 100, such that the semiconductor layers 300, 400 and 500 may be damaged during the removal of the substrate 100 or irradiation of the laser.
FIGS. 3 and 4 are views showing examples of a semiconductor light-emitting device described in Japan Laid-Open Patent Publication No. H08-083929. A rear electrode 820 is made of a conductive material, disposed on the rear surface of a substrate 100, and electrically connected to an n-type semiconductor layer 300 through a hole 110 formed in the substrate 100 and semiconductor layers 200 and 300. In order to manufacture this vertical-type semiconductor light-emitting device, considering that the rear electrode 820 is disposed on the rear surface of the substrate 100 which is an electric insulator, it is necessary to form an electrical connection or electrical path 810 in the substrate 100. However, there is a problem in that the n-type semiconductor layer 300 is damaged during a process of forming the hole 110 by a laser.